Investigators told NBC News that while there are many possible explanations for these two puzzling finds, they are hoping to get to the bottom of things immediately.

A mysterious piece of paper was also found in the shooter's hotel room, where he opened fire on the Route 91 Harvest country music festival Sunday night, killing at least 59 concertgoers and injuring more than 500.

Although investigators have confirmed it is not a suicide note, there has still been much speculation about what may have been on the paper.